Home
Class 12
MATHS
Let A(3, 7) and B(6, 5) are two points. ...

Let A(3, 7) and B(6, 5) are two points. `C:x^(2)+y^(2)-4x-6y-3=0` is a circle.
Q. If O is the origin and P is the center of C, then absolute value of difference of the squares of the lengths of the tangents from A and B to the circle C is equal to :

A

`(AB)^(2)`

B

`(OP)^(2)`

C

`|(AP)^(2)-(BP)^(2)|`

D

`(AP)^(2)+(BP)^(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the absolute value of the difference of the squares of the lengths of the tangents from points A(3, 7) and B(6, 5) to the circle defined by the equation \( C: x^2 + y^2 - 4x - 6y - 3 = 0 \). ### Step 1: Find the center and radius of the circle The equation of the circle can be rewritten in standard form by completing the square. 1. Rearranging the equation: \[ x^2 - 4x + y^2 - 6y = 3 \] 2. Completing the square for \(x\): \[ x^2 - 4x = (x - 2)^2 - 4 \] 3. Completing the square for \(y\): \[ y^2 - 6y = (y - 3)^2 - 9 \] 4. Substitute back into the equation: \[ (x - 2)^2 - 4 + (y - 3)^2 - 9 = 3 \] \[ (x - 2)^2 + (y - 3)^2 = 16 \] From this, we can see that the center \(P\) of the circle is at \( (2, 3) \) and the radius \(r\) is \(4\) (since \(r^2 = 16\)). ### Step 2: Calculate the lengths of the tangents from points A and B The length of the tangent from a point \((x_1, y_1)\) to a circle with center \((h, k)\) and radius \(r\) is given by the formula: \[ L = \sqrt{(x_1 - h)^2 + (y_1 - k)^2 - r^2} \] #### Length of tangent from point A(3, 7): 1. Substitute \(A(3, 7)\) into the formula: \[ L_A = \sqrt{(3 - 2)^2 + (7 - 3)^2 - 4^2} \] \[ = \sqrt{1^2 + 4^2 - 16} \] \[ = \sqrt{1 + 16 - 16} = \sqrt{1} = 1 \] #### Length of tangent from point B(6, 5): 2. Substitute \(B(6, 5)\) into the formula: \[ L_B = \sqrt{(6 - 2)^2 + (5 - 3)^2 - 4^2} \] \[ = \sqrt{4^2 + 2^2 - 16} \] \[ = \sqrt{16 + 4 - 16} = \sqrt{4} = 2 \] ### Step 3: Calculate the squares of the lengths of the tangents 1. Square the lengths: \[ L_A^2 = 1^2 = 1 \] \[ L_B^2 = 2^2 = 4 \] ### Step 4: Find the absolute value of the difference of the squares 1. Calculate the absolute difference: \[ |L_A^2 - L_B^2| = |1 - 4| = | -3 | = 3 \] ### Final Answer The absolute value of the difference of the squares of the lengths of the tangents from A and B to the circle C is \(3\). ---
Promotional Banner

Topper's Solved these Questions

  • CIRCLE

    VIKAS GUPTA (BLACK BOOK) ENGLISH|Exercise Exercise - 4 : Matching Type Problems|2 Videos
  • CIRCLE

    VIKAS GUPTA (BLACK BOOK) ENGLISH|Exercise Exercise - 5 : Subjective Type Problems|13 Videos
  • CIRCLE

    VIKAS GUPTA (BLACK BOOK) ENGLISH|Exercise Exercise - 2 : One or More than One Answer is/are Correct|10 Videos
  • BIONMIAL THEOREM

    VIKAS GUPTA (BLACK BOOK) ENGLISH|Exercise Exercise-4 : Subjective Type Problems|15 Videos
  • COMPLEX NUMBERS

    VIKAS GUPTA (BLACK BOOK) ENGLISH|Exercise EXERCISE-5 : SUBJECTIVE TYPE PROBLEMS|8 Videos

Similar Questions

Explore conceptually related problems

Let A(3, 7) and B(6, 5) are two points. C:x^(2)+y^(2)-4x-6y-3=0 is a circle. Q. The chords in which the circle C cuts the members of the family S of circle passing through A and B are concurrent at:

The square of the length of tangent from (2,- 3) on the circle x^(2)+y^(2)-2x-4y-4=0 is :

The length of the chord of contact of the tangents drawn from the point (-2,3) to the circle x^2+y^2-4x-6y+12=0 is:

Find the equations of the tangents from the point A(3,2) to the circle x^(2)+y^(2)+4x+6y+8=0 .

The pair of tangents from origin to the circle x^(2)+y^(2)+4x+2y+3=0 is

The length of the tangent to the circle x^(2)+y^(2)-2x-y-7=0 from (-1, -3), is

The square of the length of the tangent from (3, -4) on the circle x^2 + y^2 - 4x - 6y+3=0 is: (A) 20 (B) 30 (C) 40 (D) 50

If the length of the tangent from (f,g) to the circle x^(2)+y^(2)=6 be twice the length of the tangent from the same point to the circle x^(2)+y^(2)+3x+3y=0, then

If y= 3x+c is a tangent to the circle x^2+y^2-2x-4y-5=0 , then c is equal to :

Find the locus of a point which moves so that the ratio of the lengths of the tangents to the circles x^2+y^2+4x+3=0 and x^2+y^2-6x+5=0 is 2: 3.